#include <bits/stdc++.h>

using namespace std;
string s;
int d = 0;
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);;
    cout.tie(0);
    getline(cin, s);
    while (s[0] == ' ') s.erase(0, 1);
    while (s[s.size() - 1] == ' ') s.erase(s.size() - 1, 1);
    for (int i = 0; i < s.size(); i++)
        if (s[i] == ' ' && s[i + 1] == ' ') {
            s.erase(i, 1);
            i--;
        }
    cout << s;
    return 0;
}

# $\color{black}{\text{le}}$$\color{gray}{\text{duc}}$$\color{darkgray}{\text{trung}}$$\color{lightgray}{\text{anh}}$